public void solve() throws Exception {
int n = in.nextInt();
int[] a = new int[n];
int sum = 0;
for (int i = 0; i < n; i++) {
a[i] = in.nextInt();
sum += a[i];
}
sum /= 2;
boolean[] dp = new boolean[sum + 1];
dp[0] = true;
for (int tmp : a) {
for (int i = sum; i >= tmp; i--) {
if (dp[i - tmp]) {
dp[i] = true;
}
}
}
String ans = dp[sum] ? "YES" : "NO";
out.println(ans);
}
public void solve() throws Exception {
long a = in.nextLong();
long b = in.nextLong();
long ans = 0;
while (a != 0 && b != 0) {
if (a > b) {
ans += a / b;
a = a % b;
} else {
ans += b / a;
b = b % a;
}
}
out.println(ans);
}
public void solve() throws Exception {
n = in.nextInt();
m = in.nextInt();
graph = new char[n][m];
cracked = new boolean[n][m];
for (int i = 0; i < n; i++) {
graph[i] = in.next().trim().toCharArray();
}
sx = in.nextInt() - 1;
sy = in.nextInt() - 1;
gx = in.nextInt() - 1;
gy = in.nextInt() - 1;
cracked[sx][sy] = true;
if (sx == gx && sy == gy) {
if (graph[sx][sy] == 'X') {}
}
int scount = 0;
for (int i = 0; i < 4; i++) {
int nx = sx + dx[i];
int ny = sy + dy[i];
if (nx < 0 || nx > n - 1 || ny < 0 || ny > m - 1) {
continue;
}
if (graph[nx][ny] == '.') {
scount++;
}
}
int gcount = 0;
for (int i = 0; i < 4; i++) {
int nx = gx + dx[i];
int ny = gy + dy[i];
if (nx < 0 || nx > n - 1 || ny < 0 || ny > m - 1) {
continue;
}
if (graph[nx][ny] == '.') {
gcount++;
}
}
boolean isNeighbors = false;
for (int i = 0; i < 4 && !isNeighbors; i++) {
int nx = sx + dx[i];
int ny = sy + dy[i];
if (nx < 0 || nx > n - 1 || ny < 0 || ny > m - 1) {
continue;
}
if (nx == gx && ny == gy) {
isNeighbors = true;
}
}
if (sx == gx && sy == gy) {
if (graph[sx][sy] == 'X') {
if (scount >= 1) {
out.println("YES");
} else {
out.println("NO");
}
} else {
if (scount >= 2) {
out.println("YES");
} else {
out.println("NO");
}
}
} else if (isNeighbors) {
if (graph[gx][gy] == 'X') {
out.println("YES");
} else {
if (gcount >= 1) {
out.println("YES");
} else {
out.println("NO");
}
}
} else if (dfs(sx, sy)) {
if (graph[gx][gy] == 'X') {
out.println("YES");
} else {
if (gcount >= 2) {
out.println("YES");
} else {
out.println("NO");
}
}
} else {
out.println("NO");
}
}